The author of this article believes in the breeding range dimensions put
forth in Bellrose's classic.That is a much more conservative view of the
original nesting range than recent estimates, which have expanded the range.
However, it is worth noting that even the older estimate included the
James Bay area. Vagrants to New England must have occurred during spring and
fall migrations, particularly if they were pushed eastward by strong winds
out of the West - just as we had a few days ago when that strong cold
front came through. It is a situation similar to that which brings us the
occasional Tundra Swan(s) and larger flocks of Snow Geese. I would think that
there is a good chance that a few migratory Trumpeter Swans are joining in
with migrating flocks of Tundra Swans, most of which are now passing by to
our West as they head North. .
Anyway, here is the link to the article and the maps.
_http://www.acsu.buffalo.edu/~insrisg/nature/swans.html_
(http://www.acsu.buffalo.edu/~insrisg/nature/swans.html)